unit of cache swapping

sulekha · 10-01-2010, 01:23 AM

Hi all,

Can any one explain me the reasons why the unit of cache swapping is called a line rather than a page ?

syg00 · 10-01-2010, 03:14 AM

Methinks you are seriously mixing up terminology - post a reference.

sulekha · 10-01-2010, 06:11 AM

Quote:

Originally Posted by syg00

Methinks you are seriously mixing up terminology - post a reference.

see:-http://tldp.org/HOWTO/Unix-and-Inter...anagement.html

see the section under 8.2. Virtual memory: the detailed version

syg00 · 10-01-2010, 06:33 AM

That reference is for hardware caches - my understanding is that the data width that can be transferred concurrently is the cache line size. Probably based on (historical) physical wiring. Google might turn up something.
Software caches (like "free" shows) are based on page size. Totally different thing.
As is swap space - again, totally different thing to all of the above.

neonsignal · 10-01-2010, 07:26 PM

The 'cache line' refers not just to the page of data, but to the information associated with that page (its address tag, and other status bits). Because one thinks of this as a row in a table, it is a 'cache line'.